From 6c716f1dbdc206f4d21379a1be0e181363aa8146 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Oct 08 2018 18:51:45 +0000
Subject: Try reducing the time the lock is needed


It seems that mysql has issue deleting the project when the
pagure.exceptions.RepoExistsException is raised because of lock
timeout: Lock wait timeout exceeded; try restarting transaction

So we tried reducing the time the lock is needed by just locking
the part where it makes sense rather than the full function.
From our empirical tests it worked, future will tell if it
persists.

Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>

---

diff --git a/pagure/lib/tasks.py b/pagure/lib/tasks.py
index 27837f7..96eaae8 100644
--- a/pagure/lib/tasks.py
+++ b/pagure/lib/tasks.py
@@ -271,38 +271,43 @@ def create_project(
     """
     project = pagure.lib._get_project(session, namespace=namespace, name=name)
 
-    with project.lock("WORKER"):
-        userobj = pagure.lib.search_user(session, username=username)
+    userobj = pagure.lib.search_user(session, username=username)
 
-        # Add the readme file if it was asked
-        templ = None
-        if project.is_fork:
-            templ = pagure_config.get("FORK_TEMPLATE_PATH")
+    # Add the readme file if it was asked
+    templ = None
+    if project.is_fork:
+        templ = pagure_config.get("FORK_TEMPLATE_PATH")
+    else:
+        templ = pagure_config.get("PROJECT_TEMPLATE_PATH")
+    if templ:
+        if not os.path.exists(templ):
+            _log.warning(
+                "Invalid git template configured: %s, not found on disk",
+                templ,
+            )
+            templ = None
         else:
-            templ = pagure_config.get("PROJECT_TEMPLATE_PATH")
-        if templ:
-            if not os.path.exists(templ):
-                _log.warning(
-                    "Invalid git template configured: %s, not found on disk",
-                    templ,
-                )
-                templ = None
-            else:
-                _log.debug("  Using template at: %s", templ)
+            _log.debug("  Using template at: %s", templ)
 
-        try:
+    # There is a risk for a race-condition here between when the repo is created
+    # and when the README gets added. However, this risk is small enough that we
+    # will keep this as is for now (esp since it fixes the situation where
+    # deleting the project raised an error if it was in the middle of the lock)
+    try:
+        with project.lock("WORKER"):
             pagure.lib.git.create_project_repos(
                 project,
                 project.repospanner_region,
                 templ,
                 ignore_existing_repo,
             )
-        except pagure.exceptions.RepoExistsException:
-            session.delete(project)
-            session.commit()
-            raise
+    except pagure.exceptions.RepoExistsException:
+        session.delete(project)
+        session.commit()
+        raise
 
-        if add_readme:
+    if add_readme:
+        with project.lock("WORKER"):
             with pagure.lib.git.TemporaryClone(
                 project, "main", "add_readme"
             ) as tempclone:
@@ -329,16 +334,16 @@ def create_project(
                 master_ref = temp_gitrepo.lookup_reference("HEAD").resolve()
                 tempclone.push("pagure", master_ref.name, internal="yes")
 
-        # Install the default hook
-        plugin = pagure.lib.plugins.get_plugin("default")
-        dbobj = plugin.db_object()
-        dbobj.active = True
-        dbobj.project_id = project.id
-        session.add(dbobj)
-        session.flush()
-        plugin.set_up(project)
-        plugin.install(project, dbobj)
-        session.commit()
+            # Install the default hook
+            plugin = pagure.lib.plugins.get_plugin("default")
+            dbobj = plugin.db_object()
+            dbobj.active = True
+            dbobj.project_id = project.id
+            session.add(dbobj)
+            session.flush()
+            plugin.set_up(project)
+            plugin.install(project, dbobj)
+            session.commit()
 
     task = generate_gitolite_acls.delay(
         namespace=project.namespace,